All the paperwork displayed in the photo, which includes a copy of the assay test from the area of discovery and other valuable information about this piece are also included.

This type of specimen is generally considered to have been formed by extremely high pressure and temperatures.

What you have is a mineral matrix within this lode ore. Gold and silver tellurides are present as well as tellurides of copper. Through deep investigation of this specimen you can see various minerals that are named based on concentrations of gold, silver, copper, and other minerals. This is not flake gold. When there are combinations of different telluride minerals, they have different names. So each specimen is unique with various concentrations of minerals. Highly recommended as a display piece.

What is Kostovite? Kostovite is a fairly new mineral in association with tennantite, chalcopyrite, pyrite, native tellurium, native gold, tellurides and other minerals. Cleavage is distinct in one direction unless polished. In reflected light the mineral is creamy white, strongly anisotropic, with high reflectivity. Fine polysynthetic lamellae are characteristic. The x-ray powder diagram of kostovite is similar to those of calaverite and sylvanite. They are found either as individual grains enclosed in the other ore-forming minerals, or as aggregates. The mineral is soft and brittle. In polished section the cleavage is not discernible. It is also non-magnetic.

A short history about the acclaimed Gold Rush:

Gold Bearing Quartz is one of the world's rarest forms of natural gold. It is found underground by hard rock miners in only a few locations in the world. Most of the World's production comes from a handful of mines in Northern California. This unique formation of very difficult to find "POCKETS" of GOLD in QUARTZ is being mined 1500 to 2500 feet below the earth's surface.